The invention relates to a sheet feed tray for use in a facsimile transceiver or copying machine, and more particularly to a sheet feed tray for containing a stack of sheets which are fed into the facsimile transceiver or copying machine.
In equipment such as a facsimile transceiver or copying machine which is provided with a sheet feed mechanism for supplying an original sheet or record sheet, a sheet feed cassette is in widespread use to simplify the loading and storage of sheets and to improve the functioning of the equipment. The cassette serves as both a sheet container and a sheet receptacle. The cassette is usually provided with corner claws for feeding sheets separated one by one, and the corner claws must be moved to their inoperative position when loading sheets onto the cassette. It is difficult to perform such a moving operation of the corner claws while the cassette is mounted on the equipment such as a facsimile transceiver, for example, so that the loading of sheets on the cassette has generally been performed by removing the cassette from the equipment.
On the other hand, it is often necessary to provide a number of sheet feed cassettes which are equal in number to the kind of sheets used. By way of example, a facsimile transceiver employs both an original to be transmitted and a record sheet for reception, which must be alternately changed as the operation of the transceiver switches between a transmit mode and a receive mode. To eliminate such troublesome operation, there has been proposed an arrangement including a plurality of sheet feed cassettes containing individual sheets of different kinds and which permits a selective use of either one of the cassettes. However, there must then be provided a feed mechanism devoted to the individual cassettes as well as a cassette selection mechanism, resulting in a complex and bulky arrangement.
There has also been proposed a dual cassette comprising upper and lower cassette portions each capable of containing a different kind of sheets so that a single feed mechanism may be operated to selectively feed either sheet. While this cassette has the advantage of an integral structure, the construction of the cassettes themselves becomes complex and the loading of the sheets onto the lower cassette portion cannot be easily achieved, thereby degrading the maneuverability of the equipment.